diff --git a/src/app/compare/[slug]/loading.tsx b/src/app/compare/[slug]/loading.tsx
deleted file mode 100644
index 2597da75..00000000
--- a/src/app/compare/[slug]/loading.tsx
+++ /dev/null
@@ -1,84 +0,0 @@
-/**
- * Loading UI rendered by Next.js during navigation to /compare/[slug].
- * Picked up automatically when the route's async render is in flight,
- * which is the visible window where ad-hoc (non-curated) pairs pay the
- * full cold start cost: every loadBenchmark for every shared bench
- * fans out chain + region variant fetches. Without this file the user
- * sees a frozen current page while the browser waits on the route
- * payload; with it the visitor gets instant feedback that the compare
- * page is building.
- */
-export default function ComparePairLoading() {
-  return (
-    <main className="mx-auto max-w-5xl px-6 pt-10 pb-16 sm:pt-14">
-      <div className="h-4 w-48 bg-surface rounded animate-pulse" />
-
-      <header className="mt-8 border-b-2 border-ink pb-6">
-        <div className="h-10 w-3/4 bg-surface rounded animate-pulse" />
-        <div className="mt-4 h-4 w-full max-w-2xl bg-surface rounded animate-pulse" />
-        <div className="mt-2 h-4 w-2/3 max-w-2xl bg-surface rounded animate-pulse" />
-        <div className="mt-4 flex flex-wrap gap-3">
-          <div className="h-3 w-32 bg-surface rounded animate-pulse" />
-          <div className="h-3 w-40 bg-surface rounded animate-pulse" />
-          <div className="h-3 w-28 bg-surface rounded animate-pulse" />
-        </div>
-      </header>
-
-      <section className="mt-8 grid grid-cols-2 gap-4 sm:gap-6">
-        <div className="flex items-center gap-3 border border-rule p-4 rounded-xl">
-          <div className="h-10 w-10 rounded-full bg-surface animate-pulse" />
-          <div className="flex-1 space-y-2">
-            <div className="h-3 w-24 bg-surface rounded animate-pulse" />
-            <div className="h-2 w-40 bg-surface rounded animate-pulse" />
-          </div>
-        </div>
-        <div className="flex items-center gap-3 border border-rule p-4 rounded-xl">
-          <div className="h-10 w-10 rounded-full bg-surface animate-pulse" />
-          <div className="flex-1 space-y-2">
-            <div className="h-3 w-24 bg-surface rounded animate-pulse" />
-            <div className="h-2 w-40 bg-surface rounded animate-pulse" />
-          </div>
-        </div>
-      </section>
-
-      <section className="mt-10">
-        <p className="text-[11px] uppercase tracking-[0.18em] text-ink-muted mb-4">
-          Loading live measurements
-        </p>
-        <div className="space-y-5">
-          {Array.from({ length: 3 }).map((_, i) => (
-            <article
-              key={i}
-              className="border border-rule rounded-2xl p-5 sm:p-6"
-            >
-              <div className="mb-5 h-5 w-2/3 bg-surface rounded animate-pulse" />
-              <div className="grid grid-cols-2 gap-3 sm:gap-4">
-                <div className="rounded-xl px-4 py-4 border border-rule bg-surface/40 space-y-3">
-                  <div className="h-3 w-20 bg-surface rounded animate-pulse" />
-                  <div className="h-10 w-32 bg-surface rounded animate-pulse" />
-                  <div className="space-y-1.5">
-                    <div className="h-2 w-full bg-surface rounded animate-pulse" />
-                    <div className="h-2 w-full bg-surface rounded animate-pulse" />
-                  </div>
-                </div>
-                <div className="rounded-xl px-4 py-4 border border-rule bg-surface/40 space-y-3">
-                  <div className="h-3 w-20 bg-surface rounded animate-pulse" />
-                  <div className="h-10 w-32 bg-surface rounded animate-pulse" />
-                  <div className="space-y-1.5">
-                    <div className="h-2 w-full bg-surface rounded animate-pulse" />
-                    <div className="h-2 w-full bg-surface rounded animate-pulse" />
-                  </div>
-                </div>
-              </div>
-            </article>
-          ))}
-        </div>
-        <p className="mt-6 text-xs text-ink-muted">
-          First hit on a brand new pair can take a few seconds while the
-          per chain and per region variants fan out. Subsequent visits
-          and other users land on the cached render.
-        </p>
-      </section>
-    </main>
-  );
-}
diff --git a/src/app/compare/[slug]/page.tsx b/src/app/compare/[slug]/page.tsx
index dcf68a45..c4bff5a8 100644
--- a/src/app/compare/[slug]/page.tsx
+++ b/src/app/compare/[slug]/page.tsx
@@ -22,6 +22,7 @@ import {
   buildSharedBenches,
   canonicalisationTarget,
   fmtTs,
+  hasSharedBenches,
   latestIso,
   parseAdHocSlug,
   type BreakdownRow,
@@ -120,6 +121,14 @@ export async function generateMetadata({
   if (!pair) notFound();
   const { a, b } = await loadPairProviders(pair);
   if (!a || !b) notFound();
+  // Final SSR gate: an ad-hoc pair can have both providers resolved yet
+  // share zero benches (e.g. an RPC provider vs an oracle). Without
+  // this notFound() the page body's `shared.length === 0` check fires
+  // after loading.tsx has already streamed the shell, so the response
+  // ships HTTP 200 + skeleton + a noindex meta from not-found.tsx —
+  // exactly what crawlers indexed before this fix. Cheap: only the
+  // appearance intersection, no Prom fan out.
+  if (!hasSharedBenches(pair, a, b)) notFound();
 
   const title = `${a.name} vs ${b.name}: live OpenChainBench benchmark data`;
   const description = capDescription(
diff --git a/src/lib/compare-compute.ts b/src/lib/compare-compute.ts
index a4130be8..736fda69 100644
--- a/src/lib/compare-compute.ts
+++ b/src/lib/compare-compute.ts
@@ -248,6 +248,38 @@ export async function loadChainRegionMatrix(
   return entries;
 }
 
+/** Lightweight precheck: does this pair have at least one shared bench
+ *  after applying the whitelist + exclude rules? Pure set arithmetic on
+ *  the already-loaded provider appearances. No Prom calls, no KV
+ *  lookup, no fan out.
+ *
+ *  Used by `generateMetadata` so the route can `notFound()` BEFORE
+ *  Next.js streams the loading.tsx fallback. Without this, an
+ *  unresolvable ad-hoc pair (two real providers that share zero benches,
+ *  e.g. an RPC provider vs an oracle) ships HTTP 200 + the loading
+ *  skeleton + `<title>Page not found</title>` because the
+ *  `shared.length === 0` check inside the page body fires after the
+ *  Suspense boundary has already streamed the shell. The result was
+ *  Google indexing the skeleton with `robots: noindex` for the entire
+ *  /compare ad-hoc surface.
+ *
+ *  Mirrors the candidate-slug computation inside `buildSharedBenches`
+ *  so the two stay in lockstep. */
+export function hasSharedBenches(
+  pair: ComparePair,
+  aAppearances: Awaited<ReturnType<typeof getProvider>>,
+  bAppearances: Awaited<ReturnType<typeof getProvider>>,
+): boolean {
+  if (!aAppearances || !bAppearances) return false;
+  const aSlugs = new Set(aAppearances.appearances.map((x) => x.benchmark.slug));
+  const bSlugs = new Set(bAppearances.appearances.map((x) => x.benchmark.slug));
+  const candidateSlugs = pair.benchmarks
+    ? pair.benchmarks.filter((s) => aSlugs.has(s) && bSlugs.has(s))
+    : Array.from(aSlugs).filter((s) => bSlugs.has(s));
+  const excluded = new Set(pair.excludeBenchmarks ?? []);
+  return candidateSlugs.some((s) => !excluded.has(s));
+}
+
 /** Resolves the intersection of two providers' bench appearances, then
  *  enriches each shared bench with aggregate + per chain + per region
  *  breakdowns. Honors the pair's `benchmarks` whitelist (when set) and